Recovery of moisture for use on lighter-than-air aircraft



Feb. 23, 1937. K. VON LUDE 2,071,868

RECOVERY OF MOISTURE FOR USE ON LIGHTER-THAN-AIR AIRCRAFT Original Filed April 21, 1934 20 j Z A 1 /3 2 1 25 gwucnk Patented Feb. 23, 1 937 v UNITED STATES PATENT OFFlCE 4 2,071,888 ascovsmr or mors'ruan son use oN' LIGH'JEB-THANQHR AIRCRAFI' Kurt von Liide, Berlin, Germany Application April 21, 1934, Serial No. 1721.880

In Germany Renewed June 18,1935. v

, 3 Claims. (Cl. 183-4) This invention has for its object the recovery. as useful water for aircraft, of the moisture of atmospheric air or other moist gases, e. g. the combustion gasesof the aircraft, by means of a sorption and regeneration process, with subsequent condensation. In this process, the gases,

e. g. silica gel, and the moisture thereby adsorbed is driven off again from the sorption material by a regeneration process, e. g. by. heating, and is thus obtained either as pure water-vapour or in such high concentration in other gases, erg. air, that it can be readily condensed with the assistance of atmospheric air or any other cooling agent available..

The invention may be best understood by reference to the following specification and ac-.

companying drawing in which the'singleflgure is a schematic showing of the invention.

The invention is primarily of importance for gas-supported engine-driven aircraft with which condition of aircraft-construction, via-lightness. 35 The production of pure water-vapour or of a high vapour-concentration permits of the cooling surfaces for condensation being made small and light and, moreover, of the performance of the cooling with a relatively small quantity of extraneous air., 40 For aircraft, the latter factor is likewise extremely important, as large cooling surfaces, apart from their great weight, also oifer an extremely high resistance to the wind of flight available for' the cooling.

The regeneration of the sorption medium may I be effected by heating with the assistance of the hot exhaust gases which otherwise escape unused into the open. Instead of ear in addition to v moist atmospheric air, use may also be made of -the verymoist combustion gases from the en-' gines. Inthis case, the exhaust gases will first give up their'heat, for regeneration purposes, to

sorption medium previously saturated withmois- 55 ture and will then be brought into conjunction charged with moisture, are brought into contact with a sorption medium capable of regeneration,

quantity of the hy the purpose must be carried on the aircraft, the

-l9-of l2. v v v In operation the water-vapordaden exhaust June '7,

with fresh sorption medium .'for the purpose of giving up their .own moisture.

Also a combination of the above effects can be obtained by bringing the exhaust gases, after they have given up heat for the purpose of re- 5 generation andv after atmospheric air has beenadmixed, into contact with the sorption medium, so that the moisture both of the engine-exhaust gases and of the atmospheric air is recovered useful water. 1o

An attempt has been madeto secure the water contained in vapouror cloud-form in the atmospheric air by hygroscopic means in order to be ableto obtain the necessary increase of weight during flight. Since, on the one hand, however, 1.5 the necessary quantity of ballast is very large and,

on the other ha the correspondingly large oscopic medium required for method has not found use in practice. For ballast purposes an attempt has alsobeen made to utilize by condensation the water vapour contained in the combustion gases of the engines, but, on account of the low concentration of the water" a vapour in ,these gases, the condensers are verylarge and heavy for a relatively small resultand produce a large increase of the resistance to flight. 'Havingreference now to the drawing, there is shown at lll'the exhaust pipe from an internal combustion engine, the gas from which is selectively delivered to either adsorber l2 or l3 by' means of two-way valve l4 and pipes l5 and it. Each adsorber comprises a chamber separated into a central compartmentfl' containing the adsorbent material and the end compartments I8 and I9 by tubev sheets 20 connected by tubes 20' embedded in the adsorbent. Outlet pipesll and- 22 from the adsorbent chambers lead to thetwof way valve 23 having a pipe 25 leading to the condenser 26, air cooled and discharging through 0 pipe 21 into the'water storage tank 28. Pipe 29 leads mm the adsorbent chamber of I! to the compartment i9 or it and pipe 30 leads from, the adsorbent chamber of i3 to the compartment gas passes to the right as the valve I4 is shown to be set, through the pipe l6 and previously saturated adsorber l3 t'o indirectly heat the adsorbent' therein and drive oil? the moisture through pipe 22 by the heat of the gas. The vapor passes through pipe 22, valve. 23, and pipe 1 25 to the condenser where it iscooled atmospherically and vthe water condensed and drained into the storage tank for, use. -The "gas passing previously activated, where the moisture in the gas is adsorbed. The stripped gas out through the pipe 2|, valve 2| and exhaust pipe 24 to the atmosphere.

When the adsorber ll has,been suitably dried or'activated and the adsorber i2 saturated with water, the valves I4, 23, 2| and 22' are reversed and the same-process takes place as previously described. o

The practical emciency of the process can be recognized from the following example which is designed-fertile conditions obtaining with an airship butgis naturally generally applicable.

Assuming an average moisture content of the air of 11 guns. of per cubic metre, 10 grms. of water per cubic metre'can be adsorbed without trouble with about grms. of gel. in order therefore, to adsorb 1 kg. of water .per minute, an air-volume of, on an average, cubic metres pcrminutemustbetreatedjkgaofgelpermim" ute being in all required for the purpose. If a suitable heat-exchange apparatus is chosen, the re-generation of these 5 has. of gel by means of the warm exhaust gases, at about 380 0., from the airship's engines can be achieved by utilising the temperature drop down to about 180 C.- The weight of exhaust gases which is required for evaporating 1 kg. ofwater from the adsorbent amounts to about 25 k'gs. On the other hand, for a consumption of about 1 kg. of fuel, about 35 kgs. of exhaust gases are available, so that, with a fuel consumption of 1 kg., 35/25=1.4 kgs. of water can be recovered bythe regeneration process. The quantity of exhaust heat available is thus so large that a 40% greater weight of water can be evaporated from the adsorbent than fuel is consumed. As the periods of adsorption and regeneration are short, the .quantity of adsorbent, e. g. gel required per kg. of water-adsorption per minute is relatively small and thus an undeaovaaoa sir-ably large increase of weight due to the apparatus for obtaining the ballast water is not to be feared.

I claim: v

1. The process of recovering water to act as ballast from the exhaust gases ofan-internai .combustion motor on aircraft, the steps of passing the hot exhaust gases in heat interchange re-.

lation with amass of porous solid adsorbent mafromtheiirst mass, reversing the masses in the 1 cycle so that the second is regenerated by the hot gases and the first used to adsorb water vapor.

2;"Ihe process of recovering useful water on aircraft operated by an internal combustion motor, the steps of passing hotexhaust gases from the motor in heat interchange relation with a massof porous solid adsorbent material that has previously become charged with water adsorbed terial that charged with water from 10 only the exhaust gases, condensing water the highly concentrated water vapor gas mixture driven oi! from said mass,- passing the cooled exfrom exhaust gases from the motor, condensing water'from the highly concentrated water vapor gas mixture driven off from said mass solely by heat'taken from said exhaustga's'es, passing er- 7 haust gases from the motor through another mass .of porous solid adsorbent material to ad sorb water vapor therefrom,'and after thewater hasbeen driven df from theiirst mass, reversing themassesinthecyclesothatthesecondisregenerated by the hot gases and the'nrst used to adsorb water vapor 3. The processaccording'to claim 2 wherein theexhaustgasesilrstgiveuptheirheattodrivs on water vapor fromchargedadsorbent material andthsninacooledstatearepassedintoother adsorbent material'to have their water'vapor KURTvoIL'UDE' 

